In household refrigerators and the like, there has hitherto been a wide use of automatic ice-making device (hereinafter referred to as ice-making device) for storing and freezing water supplied from a water-supply pipe into an ice-making vessel, and releasing the produced ice cubes by means of a drive unit which turns the ice-making vessel upside down.
Description is provided hereinafter of one such ice-making device of the prior art with reference to the accompanying drawings. FIG. 26 shows an overall structure of the ice-making device in the conventional refrigerator.
FIG. 27 is a structural illustration of an ice-making unit of the conventional ice-making device. As shown in FIG. 26 and FIG. 27, main cabinet 75 of the refrigerator comprises outer cabinet 76, inner cabinet 77, and insulating material 78 filled in a space between outer cabinet 76 and inner cabinet 77. Compartment wall 79 separates the interior of the refrigerator's main cabinet 75 into upper and lower spaces. The upper space forms freezer compartment 70 and the lower space forms refrigeration compartment 71. Blower 73 forcefully delivers cold air chilled by evaporator 72 in a refrigeration cycle provided on the back wall of freezer compartment 70 in a manner to circulate through freezer compartment 70 and refrigerator compartment 71.
Ice-making device 74 disposed inside freezer compartment 70 comprises drive unit 85 having built-in motor (not shown in the figure), reduction gear (not shown) and the like, ice-making vessel 87 having support shaft 86 connected to its center part, frame 88 for turnably supporting ice-making vessel 87 to drive unit 85, and so on.
Frame 88 is provided with stopper 89 at one part of it to deform the shape of ice-making vessel 87 in order to release ice cubes. In addition, ice-making vessel 87 has flange 90 in a position to strike against stopper 89.
There is ice storage box 81 disposed underneath ice-making device 74. Water tank 82 for storing supply of water for ice making is removably placed in one section of refrigerator compartment 71. Water tank 82 has valve 84 to open and close water supply port 83.
Water reservoir 95 is located under water supply port 83 of water tank 82. When water tank 82 is placed with water supply port 83 downward, valve 84 is pushed up to open water supply port 83. Water pump 96 pumps up the water received in water reservoir 95. Water-supply pipe 97 connected to water pump 96 is disposed to open its outlet in ice-making vessel 87 of ice-making device 74.
This conventional ice-making device 74 operates in a manner as described hereinafter. When the user fills water tank 82 with water and places it in a given position, valve 84 is pushed up to open water supply port 83 and deliver the water to fill water reservoir 95. The delivered water is then pumped up by water pump 96, and supplied into ice-making vessel 87 through water pipe 97. The water of a predetermined amount thus supplied in ice-making vessel 87 is frozen by the refrigerating function inside freezer compartment 70 to form ice cubes.
Upon completion of ice making, a turning motion of drive unit 85 causes ice-making vessel 87 to turn upside down around support shaft 86 until flange 90 strikes upon stopper 89. Ice-making vessel 87 is thereby twisted and deformed to release the ice cubes into ice-making vessel 87. The released ice cubes fall in storage box 81 and they are stored therein. After the ice cubes are released, ice-making vessel 87 is returned again to the original position by a reversed turning motion of drive unit 85.
The automatic ice making and storage is continued thereafter by repeating the above operation until the water in water tank 82 is used up completely.
On the other hand, there are a number of methods that determine shapes of produced ice cubes, one of which is to use an ice-making vessel of certain shape as described in the above example of the prior art, and another one is to make a comparatively large block of plank-shaped ice and to crack it into pieces. An example of the latter method is disclosed in Japanese Patent Unexamined Publication, No. H08-86548.
Description is provided hereinafter of the above ice-cracking device of the prior art, by referring to the accompanying drawings.
FIG. 28 is a partially sectioned side view of such conventional ice-cracking device, and FIG. 29 is a longitudinally-sectioned side view of the same conventional ice-cracking device. Box-shaped frame 148 has a recessed portion 149 in the top plate, where feed opening 150 is formed for feeding a block of ice “H”. Cover 150A closes feed opening 150. The interior of frame 148 is divided into upper and lower sections by bulkhead 152 having discharge opening 151 for discharging cracked pieces of ice “K”. Container 153 for storing the cracked ice “K” is secured below discharge opening 151.
At one side of container 153 facing front opening 154, U-shaped stopper 156 is held to container 153 with pin 157 in a freely rotatable manner so that it normally stays in abutment against the back of door 155 attached to frame 148, and follows the opening and closing motions of door 155. Ice-cracking unit case 159 formed integrally with hopper 158 is secured above discharge opening 151, and hopper 158 is capable of taking a block of ice “H” having a mass of about 4 kg generally used for commercial purpose.
Upper opening 160 of hopper 158 is arranged in communication to feed opening 150.
Ice-cracking unit case 159 is provided therein with two rotors 161 and 162 mounted to shafts 163 and 164 with a predetermined distance in a freely rotatable manner, as shown in FIG. 29. Both of rotors 161 and 162 are provided with two or three arms 165 and 166 in a protruding manner at regular intervals along the axial direction thereof according to cracking sizes of ice, and first smashing pins 167 and 168 are mounted to these arms 165 and 166 respectively. Rotors 161 and 162 are also provided with two or three arms 169 and 170 at regular intervals in the same protruding manner along the axial direction, but at an angle of 180 degrees from first smashing pins 167 and 168. Arms 169 and 170 also have second smashing pins 171 and 172 mounted respectively thereto. There is provided a ridge-shaped pedestal for supporting the block of ice “H” to be cracked by first smashing pins 167 and 168 and second smashing pins 171 and 172 one after another.
The pedestal has a number of arc-shaped grooves 174 formed in areas where the tips of the smashing pins are allowed to travel through.
Ends of shafts 163 and 164 at one side of both rotors 161 and 162 are extended outside of ice-cracking unit case 159, and connected with their respective timing gears 175 and 176 in a manner that first smashing pin 167 of rotor 161 is shifted at a 90-degree angle from another first smashing pin 168 of rotor 162, as shown in FIG. 28. Shaft 164 of rotor 162 is also connected with sprocket wheel 177 which is then engaged by chain 179 to another sprocket wheel 178 fixed to a main shaft of motor M mounted to the exterior sidewall of hopper 158.
In ice-cracking device constructed as above, when a block of ice “H” is thrown in hopper 158, rotors 161 and 162 rotate, and first and second smashing pins 167, 168, 171 and 172 on rotors 161 and 162 alternately strike the block of ice “H” to crack it gradually from its leading end.
In the above structure of the conventional ice-making device, however, cubes of ice it produces have same shape at all times since a configuration of the ice-making vessel determines the shape of ice cubes. In addition, the ice cubes need to be so shaped that side faces are sloped and edges are rounded in order to release the ice cubes from the ice-making vessel by twisting it at the end of ice making. It is for this reason that the device could provide only ice cubes of undesirable shape in appearance for use in beverages such as whiskey and water.
On the other hand, the ice-making device may be equipped with an ice-cracking device to provide ice cubes of desirable shape in appearance, but this requires a conveyer unit for transferring blocks of ice from an ice-making unit through the hopper to the rotors in order for the conventional ice-cracking device to break the ice into pieces.
There was also a drawback that the ice-making device becomes quite bulky in size since the rotors must have dimensions enough to hold a block of plank-shaped ice, and the ice-making unit and the conveyer unit need respectively large capacities to carry the block of ice. Furthermore, it requires a comparatively large motor in order to deliver a large torque sufficient to break the block of ice, and this was also the factor of making the ice-making device so large.
The present invention addresses the above problems of the prior art, and to provide an ice-making device of small size, yet capable of making irregularly-shaped chips of ice not having excessively sloped side faces and rounded edges, which are desirable in appearance for use in such beverages as whiskey and water,